The goal of the Addiction Research and Treatment Corporation is to provide the means for the rehabilitation and productive re-entry of the heroin addict into society. Addiction Research and Treatment corporation is one of seventeen treatment centers who participated in the first 40 week LAAM (L=Alpha-Acetyl-Methadol)/SAODAP Cooperative Study, testing the efficacy and safety of the longer acting LAAM, as composed with methadone for treating heroin addicts in a maintenance program. The present proposal constitutes a continuation of that work for an additional 40 week period. The study includes SAODAP objectives of social adjustment, employment and reduction of arrest rate and use of illicit drugs through improved treatment. Client incentives to treatment using the longer acting LAAM are predicted largely upon the reduced clinic visit schedule and the improved medical care provided in the monitored study.